• Title/Summary/Keyword: chemical binding

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Thermodynamics of Small Electron-Bound Water Clusters

  • Lee, Sik;Lee, Han-Myoung
    • Bulletin of the Korean Chemical Society
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    • v.24 no.6
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    • pp.802-804
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    • 2003

  • The relative stabilities of weak binding clusters are sensitive to temperature due to the entropy effect. Thus, here we report significant changes in relative stabilities between two low-energy electron-water trimer structures and those between three low-energy electron-water pentamer structures, as the temperature increases. The trimer and pentamer show structural changes around 200 K.

  • https://doi.org/10.5012/bkcs.2003.24.6.802 인용 PDF KSCI

Regiospecific Protein Perturbation on F NMR Shifts and Photoisomerization of Fluororhodopsins. An Interpretation Based on Recent Crystal Structures of Rhodopsin

  • Colmenares, Letica U.;Liu, Robert S.H.
    • Journal of Photoscience
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    • v.10 no.1
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    • pp.81-87
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    • 2003

  • Based on structural information provided by recently reported crystal structures of rhodopsin, we present rationales for the regiospecific protein perturbation on the previously reported $\^$19/F chemical shifts of the vinyl and trifluoromethylrhodopsins and their photoproducts. The crystal structures also suggest that H-bonding is a likely cause for the earlier reported regiospecific photoisomerization of the 10-fluororhodopsins. Photoisomerization was revealed by chemical shift of the photoproducts. Additionally, possible use of 3-bond F,F coupling constants for following photoisomerization of retinal-binding proteins is discussed.

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N-Anthracenylmethyl Calix[4]azacrowns as New Fluorescent Ionophores

  • Yang, Seung-H.;Shon, Ok-J.;Park, Ki-M.;Lee, Shim-S.;Park, Ho-J.;Kim, Moon-J.;Lee, Joung-H.;Kim, Jong-S.
    • Bulletin of the Korean Chemical Society
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    • v.23 no.11
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    • pp.1585-1589
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    • 2002

  • Two novel calixarene-based fluoroionophores were synthesized. Their conformations were confirmed to 1,3-alternate by X-ray crystal structures. From CHEF by blocking the PET mechanism in fluorescence spectra, we observed $In^{3+}$ and $Pb^{2+}$ selectivity over other metal ions. For $In^{3+}$ion, calix[4]-bis-azacrown-5 showed about 20 times more sensitive than calix[4]-mono-azacrown-5 because the source of the binding selectivity comes from the calixarene framework and azacrown ligand by controlling the fluorescence and PET mechanisms as-sociated with the amine moiety.

  • https://doi.org/10.5012/bkcs.2002.23.11.1585 인용 PDF KSCI

Leucine Rich Repeat Sequence of the ${\delta}$ Endotoxin Family of Bacillus thuringiensis

  • Vudayagiri, Suvarchala;Jamil, Kaiser
    • BMB Reports
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    • v.33 no.1
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    • pp.89-91
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    • 2000

  • In this investigation we report our search for the presence of Leucine Rich Repeats (LRRs) in various Bacillus thuringiensis (Bt) sub species. Leucine rich repeats are short sequence motifs present in some proteins. The consensus sequence corresponding to the LRR was present in Crystal proteins of Bacillus thuringiensis sub species. This LRR sequence has been predicted to be involved in proteinprotein interactions or receptor binding functions, hence the importance of this study.

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